Biomedical subjects

J A Weststrate

Publications and source records attributed to J A Weststrate.

At least 37 records · Page 2Linked to original sources

PubMed1998

Energy intake and body weight effects of six months reduced or full fat diets, as a function of dietary restraint.

OBJECTIVE: Assessment of the effect of six months consumption of reduced fat or full fat products on energy intake and body weight, as a function of dietary restraint. DESIGN: A small realistic supermarket in the University departments provided full fat commercial products and their reduced fat alternatives. Volunteers visited the supermarket once a week. Half of them were required to take the reduced fat products, the other half the full fat products. They bought additional products in normal shops. SUBJECTS: Two matched groups (age, genders, body mass index (BMI)), one dietary restrained and one dietary unrestrained, were derived from the total group of 220 healthy men and women. This resulted in four groups differing in dietary restraint and in belonging to the full fat or reduced fat group. MEASUREMENTS: Energy intake, macronutrient composition of food intake, energy density and weight of food ingested were measured before the run-in period and at 2-4 weeks, three and six months after the start of the study, by controlled food intake diaries. RESULTS: Percentage energy from fat, and energy density changed significantly, according to the reduced or full fat diet, in all subjects. Energy intake and body weight remained constant in the dietary unrestrained on a reduced fat diet and in the dietary restrained on a full fat diet. Energy intake increased significantly, with a trend of body weight increase in the dietary unrestrained on a full fat diet. Body weight decreased significantly, with a trend of decreased energy intake, in the dietary restrained on a reduced fat diet. CONCLUSION: A reduced fat diet, in combination with unrestrained eating behaviour which resulted in energy intake compensation, contributed to weight maintenance. Weight reduction was the consequence of a reduced fat diet in combination with restrained, non-compensatory eating behaviour. A full fat diet combined with unrestrained eating behaviour led to increased energy intake. Restrained eating behaviour with a full fat diet prevented an increase in energy intake and body weight. Thus dietary restraint compensated for an increase in energy density, whereas dietary unrestraint compensated for a decrease in energy density.

Adult↗

PubMed1998

Effects of margarine compared with those of butter on blood lipid profiles related to cardiovascular disease risk factors in normolipemic adults fed controlled diets.

Effects of butter and 2 types of margarine on blood lipid and lipoprotein concentrations were compared in a controlled diet study with 23 men and 23 women. Table spreads, added to a common basal diet, provided 8.3% of energy as fat. Diets averaged 34.6% of energy as fat and 15.5% as protein. Each diet was fed for 5 wk in a 3 x 3 Latin-square design. One margarine (TFA-M) approximated the average trans monoene content of trans fatty acid-containing margarines in the United States (17% trans fatty acids by dry wt). The other margarine (PUFA-M) was free of trans unsaturated fatty acids; it contained approximately twice the polyunsaturated fatty acid content of TFA-M (49% compared with 27% polyunsaturated fatty acids). The tub-type margarines had similar physical properties at ambient temperature. Fasting blood lipids and lipoproteins were determined in 2 samples taken from the subjects during the fifth week of each dietary treatment. Compared with butter, total cholesterol was 3.5% lower (P=0.009) after consumption of TFA-M and 5.4% lower (P< 0.001) after consumption of PUFA-M. Similarly, LDL cholesterol was 4.9% lower (P=0.005) and 6.7% lower (P< 0.001) after consumption of TFA-M and PUFA-M, respectively. Neither margarine differed from butter in its effect on HDL cholesterol or triacylglycerols. Thus, consumption of TFA-M or PUFA-M improved blood lipid profiles for the major lipoproteins associated with cardiovascular risk when compared with butter, with a greater improvement with PUFA-M than with TFA-M.

Adult↗

PubMed1997

Energy and fat compensation during long-term consumption of reduced fat products.

The objective of this study was to investigate the behavioral response to the long term realistic consumption of reduced fat products. During six months, a control group of 103 subjects had free access to about 45 commercially available full-fat products, and a reduced-fat group of 117 subjects had access to the reduced fat equivalents. These experimental products covered about 37% of total energy intake in the control group and 30% of energy intake in the reduced fat group. Other non-experimental food products were bought in regular shops. The results showed that, compared to a baseline measurement before the start of the study, energy intake increased from 10.4 MJ/day to 11.2 MJ/d in the control group, whereas it remained constant at 10.2 MJ/d in the reduced fat group. Fat intake in the control group increased from 99 g/d (35.6en%) to 123g/d (40.6en%), whereas fat intake in the reduced fat group decreased from 95 g/d (34.en%) to 90 g/d (32.7en%). The energy and fat intake from experimental products was lower in the reduced fat group (3.1 MJ/d, 37 g fat/d) than in the control group (4.2 MJ/d, 71 g fat/d). There was some compensatory response in the consumption of experimental products: the ingested amount of experimental products was about 10% higher in the reduced fat group (447 g/d) than in the control group (399 g/d)[t = 2.6; p < 0.01]. There was no compensatory response in the consumption of non-experimental products. Both the control and reduced fat group consumed about 7.1 MJ/d and 53 g fat/d from non-experimental products. It is concluded that long term consumption of reduced fat products leads to a lower energy and fat intake, compared to the consumption of full-fat products.

Adult↗

PubMed1997

Effects of green tea, black tea and dietary lipophilic antioxidants on LDL oxidizability and atherosclerosis in hypercholesterolaemic rabbits.

The hypothesis that tea or dietary lipid-soluble antioxidants reduce atherogenesis by lowering the oxidizability of low-density lipoprotein (LDL) was investigated. Five groups of 20 female New Zealand white rabbits were fed a restricted amount of a high-fat (30 en%) semipurified diet supplemented with cholesterol (0.15%, w/w) for 21 weeks. The vitamin E content of the control diet was 40 mg/kg diet. The animals received either green tea or black tea in their drinking water or vitamin E (200 mg/kg diet) or beta-carotene (20 mg/kg). The serum cholesterol concentrations (in the order of 18-23 mmol/l) were not significantly different between the groups. Vitamin E was substantially increased as compared to controls in vitamin E supplemented animals (3-fold within 8 weeks in plasma and LDL; P < 0.01) and weakly (1.2-fold) by green and black tea (P < 0.05). Green tea consumption tended to reduce aortic lesion formation by 31% (24 +/- 3.2% versus 35 +/- 5.7% for control animals P = 0.11), while black tea, vitamin E and beta-carotene had no effect. This was in contrast to the resistance of isolated LDL to oxidation induced at high copper concentration. Green and black tea induced a 13% and 15% (P < 0.05) prolongation of the lag phase, respectively, with a correspondingly lower oxidation rate, while vitamin E increased the lag phase by 63% (P < 0.01) with a concomitant diminution of the oxidation rate and beta-carotene had no effect. Regression analysis showed that there was no relationship between the extent of atherosclerosis and LDL oxidizability or plasma malondialdehyde as marker of in vivo lipid peroxidation. The results of the present study raise the question whether LDL oxidizability (at least when tested at high induction rate ex vivo) is a primary causal mechanism in atherosclerosis in the cholesterol-fed rabbit. The suitability of the cholesterol-fed rabbit with extreme hypercholesterolaemia as a model to study antiatherosclerotic properties of dietary antioxidants, such as the tested polyphenols, is discussed.

Animal Feed↗

PubMed1997

Diet-induced thermogenesis and satiety in humans after full-fat and reduced-fat meals.

Diet-induced thermogenesis was measured during and after a full-fat lunch, an identical but reduced-fat, reduced-energy lunch, and an iso-energetic reduced-fat lunch in 32 normal-weight men and women, age 35-55. Hunger and satiety were scored during and after the lunches, and their relationship to diet-induced thermogenesis was assessed. Diet-induced thermogenesis was relatively higher after the reduced-fat, reduced-energy lunch compared to the full-fat lunch (6.7% vs. 5.2%; p < 0.05). The respiratory quotients were significantly lower after the full-fat lunch than after the 2 reduced-fat lunches (p < 0.05). After the iso-energetic reduced-fat lunch, hunger scores were significantly reduced and satiety scores significantly increased (p < 0.05) until 1800 h. compared to the other 2 lunches. Satiety scores were positively related to the magnitude of diet-induced thermogenesis expressed as an absolute increase in metabolic rate during and after the meal. We conclude that hunger and satiety scores, substrate utilization, and diet-induced thermogenesis showed clear and different short-term responses to diets that differed with respect to the percentage energy from fat and/or the energy content of the meal.

Adult↗

PubMed1997

Effect of replacement of fat by nonabsorbable fat (sucrose polyester) in meals or snacks as a function of dietary restraint.

The effect of replacement of fat by nonabsorbable fat on energy intake and on feelings of hunger and satiety was assessed, in normal-weight dietary-restrained (n = 11), dietary-unrestrained (n = 13) and in postobese dietary-restrained women (n = 12), using 2 experimental designs. First, during breakfast and lunch on 2 sequential weekdays, 23 g of dietary fat was replaced by 23 g of a nonabsorbable fat. Second, dietary fat was replaced by a nonabsorbable fat in snacks consumed ad lib during a different week. Fat replacement in meals or in snacks did not result in changes in hunger and satiety ratings throughout the day. Replacement in meals yielded an energy intake reduction of 0.5 MJ/day (not significant) in dietary-unrestrained and in postobese dietary-restrained subjects; this reduction included 44% energy intake compensation. In normal-weight dietary-restrained subjects, energy intake reduction of 0.7 (p < 0.05) MJ/day was observed; this reduction included 22% energy intake compensation. Moreover, fat replacement in meals showed a shift in macronutrient composition from 35-40% energy from fat to 31-32% energy from fat. Replacement in snacks yielded an energy intake reduction of 0.4-0.5 MJ/day (not significant) in normal-weight dietary-restrained subjects and a reduction of 0.6-0.7 (p < 0.05) MJ/day in dietary-unrestrained and in postobese dietary-restrained subjects. In this situation, energy intake from snacks consisted of 48-78% energy from reduced-fat reduced-energy snacks, which implied a replacement of 10-15 g fat by 10-15 g SPE (sucrose polyester) and a shift in macronutrient composition from 35-40 percentage energy from fat to 33-36 percentage energy from fat. These results suggest short-term beneficial effects of fat replacement on energy and fat intake.

Adult↗

PubMed1997

Interesterification of fats in margarine: effect on blood lipids, blood enzymes, and hemostasis parameters.

OBJECTIVES: In 60 healthy humans, a blend of commonly used edible vegetable fats was compared with the same fat blend after random chemical interesterification, for their effects in terms of nutritional safety on blood lipids, blood enzymes and hemostasis parameters. DESIGN: Both fat blends were supplied double-blind at two energy levels (4 and 8% of energy) in margarine according to a parallel design. At either energy level, the two fat blends were consumed according to a cross-over design for two periods of three weeks, without an intermediate wash-out period. RESULTS: The 30 parameters studied revealed no statistically significant differences between the two fat blends, except for slightly (approximately 10%) lower D-dimers concentrations after consumption of the interesterified fat blend. CONCLUSIONS: Increased levels of the fibrin-degradation products D-dimers are positively associated with risk for coronary heart disease. Thus, it was concluded that the inclusion of a chemically interesterified vegetable fat blend in the diet of healthy people does not influence fasting blood lipids, blood enzymes and/or hemostasis parameters in an adverse way, when compared with a non-interesterified fat blend with the same fatty acid composition.

Adult↗

PubMed1997

Dietary linoleic acid at high and reduced dietary fat level decreases the faecal excretion of vitamin E in young rats.

Vitamin E is the major lipid-soluble antioxidant in human subjects and is crucial in protecting polyunsaturated fatty acids (PUFA) against lipid peroxidation. Dietary PUFA have been suggested to inhibit the absorption of vitamin E. The present study in young male rats was designed to investigate the effect of increasing concentrations of dietary linoleic acid on the faecal excretion of vitamin E. The rats were fed on semi-synthetic diets containing two concentrations of fat (59 g/kg diet, 15 energy % (en%) or 131 g/kg, 30 en%) for 3 weeks. Triacylglycerol rich in linoleic acid was added at the expense of triacylglycerol rich in saturated fatty acids to obtain dietary concentrations of 13, 39 or 66 g linoleic acid/kg diet for the high-fat diet (131 g fat/kg) and 12, 24 or 36 g linoleic acid/kg diet for the reduced-fat diet (59 g fat/kg). The results from the present study demonstrate that the faecal excretion of vitamin E was significantly lower in rats fed on diets with high levels of linoleic acid compared with rats fed on lower levels of linoleic acid irrespective of the dietary fat content. The concentration of vitamin E in liver and plasma was significantly lower in animals fed on the highest concentration of linoleic acid compared with those fed on the lowest level. Results from the present study also demonstrate that at the same concentration of linoleic acid, the faecal excretion of vitamin E in rats fed on reduced-fat diets was significantly lower than in rats fed on high-fat diets. Our findings indicate that the apparent absorption of vitamin E is not inhibited by dietary PUFA. Results from the present study also demonstrate that a reduction of dietary fat content from 30 en% to 15 en% does not lower the apparent absorption of vitamin E.

Animals↗

PubMed1997

A long-term study on the effect of spontaneous consumption of reduced fat products as part of a normal diet on indicators of health.

The growing public concern with the adverse effects on health of a high fat intake has led to a proliferation on the market of reduced fat products. However, no consensus exists on the effectivity of reduced fat products to decrease energy intake. The studies that have investigated this topic have included small numbers of subjects, studied under laboratory conditions and over a relatively short period of time. Therefore, we have executed a long-term study in which volunteers had free access to both reduced fat, commercially available products in the laboratory as well as to products obtained from regular shops. We here report the feasibility of such a type of study and the effects of consumption of reduced fat products on blood levels of cholesterol, haemostasis variables, antioxidants and parameters of the immune system. The study was a multicentre parallel comparison trial of six months (so-called MSFAT-study). 241 volunteers received either reduced fat products or full-fat products and the products were clearly labelled as such. Two months before the start of the study, a 1 month adaptation period was executed to optimize the experimental procedures. Food intake was recorded before the start of the adaptation period and 2-4 weeks, 3 months and 6 months after the start of the study. Blood samples were taken before, after 2, 4 and 6 months of the study. In addition, a selection of the reduced fat and full-fat products was sensorically evaluated three times during the study by a subgroup of the volunteers. 220 volunteers completed the study. The reduced fat group consumed on average 46% less fat from the so-called MSFAT-products obtained from the shop at the laboratory than the control group and consumption of these MSFAT-products did not decrease in either of the groups during the time course of the study. The palatability of the reduced fat and full-fat products was similar and as expected, the perceived fattiness of the full-fat products was higher than that of the reduced fat products. No effects were found on blood levels of cholesterol, haemostasis variables, parameters of antioxidant status and immune system characteristics. In conclusion, the experimental manipulation of the fat content of the diet that was achieved and that remained stable throughout the 6 months of the study indicates that this type of set-up is feasible to assess the effects of long-term nutritional intervention in large groups of volunteers under semi-controlled conditions. The regular use of reduced fat products did not positively but also not adversely affect blood cholesterol levels, antioxidant status, haemostasis factors and the body's immune system.

Adult↗

PubMed1996

[Long-term effects of nutrition with fat-reduced foods on energy consumption and body weight].

UNLABELLED: In a 3-month intervention study 70 women (40 < age < 60; 24 < BMI < 29), randomized into two groups, were supplied ad libitum and free of charge with 1) customary fat-reduced foods (D group) or 2) products with normal fat content (K group). After 6 months without any contact to the volunteers food intake and body weight were controlled. RESULTS: During the intervention period fat intake (by 22 g/d) and total energy intake (by 266 kcal/d) of the volunteers in the D group were significantly lower than in the K group. Fat reduction was not accompanied by a compensative increase in the intake of other nutrients. The weight loss was significant in the D group (1.5 kg) and not significant in the K group (0.7 kg). Between the two groups the difference in weight reduction was not significant. In the follow-up a lowered fat and energy intake had been voluntarily retained in the D group and adopted by most of the individuals in the K group. CONCLUSION: The consumption of low-fat products lowers the energy and fat intake and may be useful for a long-term weight control and health support.

Adult↗

PubMed1996

Long-term effects of consumption of full-fat or reduced-fat products in healthy non-obese volunteers: assessment of energy expenditure and substrate oxidation.

A study was performed to evaluate long-term (6-month) effects of consumption of full-fat products or reduced-fat products on energy and substrate metabolism. Subjects (age, 19 to 35 years; body mass index [BMI], 21 to 28 kg. m-2) were studied during a 36-hour stay in a respiration chamber, before (16 men) and in the third month (16 men) and sixth month (19 men and 17 women) of the study. The diet intervention caused, on average, a change in fat intake of (mean +/- SE) +23 +/- 31 g/d (P < .001) in the full-fat group and of -5 +/- 29 g/d (P .05) in the reduced-fat group. Twenty-four-hour energy expenditure (EE), sleeping metabolic rate (SMR), diet-induced thermogenesis (DIT), and EE for physical activity (ACT) were not different between the groups. Fat oxidation was significantly (P < .05) increased in the full-fat group and was not different from fat intake. During the 6 months of the study, body mass and fat mass were significantly increased in subjects of the full-fat group, whereas there were no changes in body mass or body composition in subjects of the reduced-fat group. It is concluded that in the long run, avoidance of a diet with full-fat products will promote body weight and fast stability.

Adult↗

PubMed1996

Energy expenditure and physical activity in subjects consuming full-or reduced-fat products as part of their normal diet.

It has been suggested that energy expenditure is higher in subjects consuming reduced-fat, high-carbohydrate diets than in subjects consuming full-fat, low-carbohydrate diets. In a 6-month randomized, controlled trial, seventeen women and twenty men (age 20-35 years; BMI 22-28 kg/m2) had free access either to a range of about forty-five reduced-fat products or the full-fat equivalents. At the end of the 6 months, energy intake, sleeping metabolic rate (SMR), average daily metabolic rate (ADMR), and physical activity (AO) were measured. The intervention resulted in a mean difference of the change of the fat content of the diet of 6% of energy (P < 0.01) between the two groups. SMR. ADMR and AO were virtually the same in both groups. The results suggest that the change in fat content of the diet has no effect on physical activity and energy expenditure. However, subjects with a higher activity level consumed more carbohydrate (ADMR/SMR: r = 0.49, P < 0.01: AO: r = 0.57, P < 0.001).

Adult↗

PubMed1996

Fat substitution and food intake: effect of replacing fat with sucrose polyester at lunch or evening meals.

The objective of the present study was to determine the effect of replacement of fat by sucrose polyester (SPE) within a lunch or evening meal on subsequent energy intake and appetite control. The 2 x 2 design was intended to examine the effect on appetite of reducing the total energy and fat content of a meal (lunch or dinner) by replacement of natural fat with 55 g SPE. The effects were monitored by measuring motivation to eat or actual food consumption during the remainder of the test day (day 1) and throughout the following day (day 2). The 2 x 2 design yielded four conditions which were a control meal (5192 kJ, 73.2 g fat) and a fat-replaced meal (3305 kJ, 54.6 g SPE, 24 g fat) at midday (lunch) or in the early evening (dinner). No significant differences were seen in ad lib. energy intake after the test meals on day 1 or day 2. Certain differences were detected in fat intake on day 2 but these did not suggest nutrient compensation in response to the fat replacement. Subjective assessment of motivation to eat did not indicate that the fat-reduced meal had a weaker satiating efficiency than the control meal. A reduction in fat content, using fat replacement, did not reduce the satiating efficiency of a test meal given at lunch or dinner. No energy or macronutrient compensation occurred following the reduction in energy or fat intake during the rest of the test day or during the whole of the next day.

Adult↗

PubMed1996

Effects of two dietary fat levels and four dietary linoleic acid levels on mammary tumor development in Balb/c-MMTV mice under ad libitum feeding conditions.

The relationship between dietary fat intake (level and type) and the development of breast cancer in humans is a matter of concern in Western society. A high fat intake is associated with a greater mammary cancer risk in humans and in animal models. Higher intake of polyunsaturated fatty acids in humans shows little or no association with mammary tumor development in epidemiologic surveys. From literature data, it appears that a higher intake of polyunsaturated fatty acids (linoleic acid) is related to an increase in mammary tumorigenesis in animal studies in which chemical carcinogens like dimethylbenz[a]anthracene are used as tumor initiator. Mostly the latency period of these chemically induced models in rather short. In this study, the Bald/c-MMTV (mouse mammary tumor virus) mouse strain was chosen as an animal model: MMTV leads to tumor initiation, and dietary factors influence tumor promotion over a relatively long latency period. The mice were fed diets with two fat concentrations: a high [36% of energy (en%)] or low (16 en%) fat level; fat was isocalorically replaced by carbohydrates (cornstarch). At both dietary fat levels, linoleic acid was given at four levels: 2, 3, 6, and 10 en%. Linoleic acid-rich fat was isocalorically replaced by oleic acid-rich fat. The diets were consumed ad libitum over a lifetime. Animals were euthanized as soon as mammary tumor diameter was > or = 1 cm or when the animals were in a poor clinical condition. The incidence of mammary tumors at 18 months was significantly higher in one group only: 36 en% fat and 2 en% linoleic acid. This group also showed the shortest mean latency period for mammary tumor development. Mean mammary tumor incidence was higher and mean onset time shorter in the four high-fat groups than in the low-fat groups. No (linear) dose-response relationship between dietary linoleic acid concentration and mammary tumor incidence and latency period was observed. This indicates that a higher dietary linoleic acid intake does not increase the incidence or shorten the latency period of breast cancer in the Balb/c-MMTV mouse strain at two different dietary fat levels.

Animals↗

PubMed1996

Replacement of dietary fat with sucrose polyester: effects on energy intake and appetite control in nonobese males.

In previous experiments using the fat substitute sucrose polyester (SPE, or olestra), no compensatory response was observed on day 2 after experimental manipulations, which reduced the percentage of energy from fat to approximately equal to 30% from 40% on day 1. In the present study a more severe manipulation was made; the amount of energy from fat was reduced from 32% to 20% to determine whether such a reduction would provoke any physiologic or behavioral response. Subjects came to the unit for two, 2-d test sessions. Intake on day 1 was fixed: subjects were given meals containing either control fat (11319 kJ, 32% of energy as fat) or SPE (9561 kJ, 20% of energy as fat). On day 2, intake was ad libitum. On day 1 subjects rated themselves as more hungry while consuming the fat-substituted meals than when consuming the control meals and they disclosed greater hunger in the end-of-day questionnaires. The effect of the manipulation was carried over into day 2. By the end of day 2, subjects had compensated for 74% of the energy (fat) deficit caused by the previous day's manipulation. These results differ from those obtained when fat was reduced from 40% to 30% of energy; this more severe reduction reveals that a reduction in fat of this size can lead to a biobehavioral response. Together, these data suggest that people could change their diet to meet dietary guidelines; however, if a more severe reduction is attempted, adherence may be made more difficult by the strength of the compensatory response.

Adult↗

PubMed1996

Nonabsorbable fat (sucrose polyester) and the regulation of energy intake and body weight.

A substantial number of people have difficulties in controlling their body weight and energy/fat intake. Fat substitutes may be helpful in solving these problems. We here report the first study on the longer-term effects of the nonabsorbable fat sucrose polyester (SPE) on energy intake in normal-weight subjects. We studied the longer-term (12 days) effects of the consumption of warm meals with normal dietary fat (5.0 MJ, 1,195 kcal) or meals in which 52 g of fat were replaced by the fat replacer SPE (3.1 MJ, 740 kcal) on spontaneous food intake (measured by dietary records), body weight, and gastrointestinal complaints in healthy volunteers in two studies. In the first study the 48 subjects were unaware of the treatment, whereas in the second study the 47 subjects were informed of what they received. In both studies men and women consumed less energy per day during the SPE (11.2 MJ) compared with the fat treatment (12.7 MJ) (P values < 0.0001) for the whole 12-day period. This was accompanied by equivalent changes in body weight. The percentage of energy from fat decreased from 43% during the fat treatment to 32% during the SPE treatment. During the SPE treatment, more gastrointestinal complaints and a higher frequency of defecation were reported. Information about the treatment did not affect. the outcomes. It is concluded that the use of a fat replacer such as SPE helps in reducing fat and energy intake in normal-weight people.

Adult↗

PubMed1996

Consumption of reduced-fat products: effects on parameters of anti-oxidative capacity.

OBJECTIVE: Dietary fat intake is higher than recommended in most western countries and is associated with the prevalence of cardiovascular diseases, obesity and cancer. The growing public concern about the adverse effects of a high fat intake has led to an increased availability of ¿reduced-fat' products. Consumption of reduced-fat products might be a convenient way to reduce the energy intake. Besides the potential of reduced-fat products to reduce the energy intake, it might change dietary fat intake, both qualitatively and quantitatively, which in turn might also affect oxidative stress, i.e. the anti-oxidant/pro-oxidant ratio. In this paper we present the effects of 6-month consumption of reduced-fat products on body weight, energy, macronutrient and vitamin E intake, concentration of the plasma lipid peroxidation product malondialdehyde (MDA), erythrocyte free radical scavenging enzymes activities (glutathione peroxidase activity (GSH-Px); superoxide dismutase (SOD) and catalase) as well as plasma fat-soluble anti-oxidative vitamin concentrations (beta-carotene, lycopene and alpha-tocopherol). DESIGN: A randomized semi-controlled parallel comparison trial of six months, preceded by a one-month adaptation period. SETTING: The reduced-fat and full fat products were provided through a realistic shop in order to mimic a ¿free-living' situation. SUBJECTS: Subjects were recruited from respondents on advertisements. Eighty healthy, normal weight (BMI: range 20-30 kg/m2) subjects, aged between 20 and 55y, were selected to participate in this study; 76 subjects completed the study. INTERVENTIONS: 6 months consumption of either reduced-fat or full-fat products. RESULTS: During the intervention period, consumption of reduced fat products resulted in significantly lower energy intake, in a lower percentage of energy derived from saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids as well as in lower vitamin E intake, when compared to the control group. Body weight, the ratio polyunsaturated fatty acids/saturated fatty acids, plasma MDA, vitamin concentrations (beta-carotene, lycopene and alpha-tocopherol), and erythrocyte free radical scavenging enzyme activities (SOD, GSH-Px and catalase) were not affected by the intervention. CONCLUSION: Neither the difference in energy intake, nor the change in dietary fat composition seems to affect the integrity of the antioxidant scavenging capacity, assessed by measuring plasma MDA and antioxidative vitamins (lycopene, beta-carotene and alpha-tocopherol) and erythrocyte free radical scavenging enzymes (SOD, GSH-Px and catalase).

Adult↗

PubMed1996

Dietary fat and body fat: an intervention study.

OBJECTIVE: Assessment of body composition in relation to the habitual diet and after a six month dietary intervention. DESIGN: After a baseline measurement subjects were randomly assigned to either a group consuming reduced-fat products or a group consuming full-fat products for six months. SUBJECTS: 108 women and 109 men, equally distributed over the age range 19-35 with BMI between 21 and 28, and the age range 36-55 with BMI between 24 and 30. MEASUREMENTS: Food intake was measured by three day dietary record, body composition by deuterium dilution. RESULTS: At baseline, explained variance of %body fat on age and fat-carbohydrate ratio in the diet together were 17% (P < 0.0001) and 36% (P < 0.0001) for women and men, respectively, and on diet alone 7-8% (P < 0.01) independent of gender. The diet intervention caused on average a change in fat intake and body fat mass in subjects of the reduced-fat group of -5 +/- 29 g/d (P < 0.05) and -0.1 +/- 2.1 kg (ns), respectively, and of +23 +/- 31 g/d (P < 0.0001) and +0.5 +/- 2.3 kg (P < 0.05) in subjects of the full-fat group. The change in the fat content of the diet was positively related to a change in energy intake (fat-carbohydrate ratio: R2 = 0.15, P < 0.0001; g fat: R2 = 0.70, P < 0.0001), the latter explaining 5% of the variation in the change in body fat mass (P < 0.001). Subjects changing the fat content of the diet showed a consequent change in body fat mass only when energy intake changed as well. CONCLUSION: The fat content of the diet has an effect on body fat as a function of the effect of dietary fat on energy intake.

Adipose Tissue↗